1. Field of Invention
This invention relates generally to the field of gear bearings and more specifically to a novel, inexpensive approach to distribute non-axial forces applied to a gear bearing without the use of a separate roller.
2. Background of the Invention
Gear bearings have become known in the art. Specifically, U.S. Pat. No. 6,626,792, to John M. Vranish, inventor of this invention, entitled Gear Bearings, discloses a novel system that performs both gear and bearing functions simultaneously. This is accomplished by providing first and second interacting gears, each having a plurality of teeth. Each of these gears is capped by an end roller, which has a radius equal to that of the pitch radius of the gear. Further, each gear tooth has a curved crown, or transition, which extends from the end of the tooth to the end roller. Importantly, the radius of the crown is the same as the end roller radius and the pitch radius. Because these three radii are identical, they move together at the same speed.
During interaction, the crown of each gear interfaces with the end roller of the other and the teeth of each gear interact with the teeth of the other at contact points, which are located at the pitch radius.
This alignment may be applied in any number of different configurations, for example a planetary system in which three or more planetary gears surround and interact with a central sun gear. The planets in turn are surrounded by and interact with a ring gear, which, not surprisingly, has corresponding teeth, crown and end roller. And the pitch radius of the ring gear, the radius of the crown and the radius of the ring end roller are the same.
A main purpose of the end roller in this embodiment of the gear bearing is to facilitate smooth rotation of the gears, i.e. prevent binding and act as a bearing, especially when a non-axial load is acting against the gear bearing. For example, when a non-axial load is applied to a gear bearing, the resulting deformation, tiny though it may be, may cause the interacting teeth to contact each other at locations other than the intended contact points at the designed radius. This variation of the intended contact points causes the gear bearing to experience increased friction, bind up and possibly even jam. The addition of an end roller prevents the teeth from engaging each other in a manner in which binding can occur.